Q. Consider the following statements about evolution of the Himalayan Rivers:
- The Shiwalik or Indo-Brahma River traversed the entire longitudinal extent of the Himalaya from Assam to Punjab and onwards to Sind during the Pleistocene period.
- It dismembered into three main drainage systems during the Miocene period.
Which of the above is / are correct?
Answer:
None of the above
Notes: Geologists believe that a mighty river called Shiwalik or Indo-Brahma traversed the entire longitudinal extent of the Himalaya from Assam to Punjab and onwards to Sind, and finally discharged into the Gulf of Sind near lower Punjab during the Miocene period some 5-24 million years ago. It is opined that in due course of time Indo-Brahma river was dismembered into three main drainage systems:
- (i) the Indus and its five tributaries in the western part;
- (ii) the Ganga and its Himalayan tributaries in the central part; and
- (iii) the stretch of the Brahmaputra in Assam and its Himalayan tributaries in the eastern part.
The dismemberment was probably due to the Pleistocene upheaval in the western Himalayas, including the uplift of the Potwar Plateau (Delhi Ridge).